I think also, the thing that's odd is that we're now living in a second-stage media world anyway. One of the reasons that both Joss and I can do some of the stuff that we've done over the years is because you're working in a medium in which enough stuff has simply entered popular culture that it becomes part of the vocabulary that we can deal with. The materials of fantasy, of all different kinds of fantasy, the materials of SF, the materials of horror...it's pop culture. It's tattooed on the insides of our retinas. As a result, it's something that's very easy just to use as metaphor. You don't have to explain to anybody what a vampire is. You don't have to explain the rules. Everybody knows that. They know that by the time they're five.

It's good and all, but it also means you can write a "science fiction" story with spaceships and stuff aimed at a general audience, just so long as you're careful to base it on pop culture and not include any actual new physics. Or similarly write "fantasy" will orcs and stuff in it, just so long as you don't invent some novel form of magic.

There's an awful lot of crap SF/F these days, written in just this way.